The Research Of Combinatorial Theory On Key Pre-distribution Schemes For Distributed Sensor Networks

Distributed sensor networks are ad-hoc networks that include a lot of tiny sensors with limited sensibility, computation and communication capabilities.the sensor networks are integration of sensor techniques, nested computation techniques, distributed computation techniques and wireless communication techniques. they can be used for testing,sensing,collecting and processing information of monitored objects and transferring the processed information to users. so they are wide applied in many fields such as military operation, country security, environmental monitoring, traffic monitoring,medical treatment hygiene, manufacturing industry, monitoring of terrorism and disaster. in 1999, the famous American Business Week [12]regard sensor networks as the most influential twenty-one technology in 21 century, and in the report on technology improvement ,Technology Review regard sensor networks as one of ten new technology that will chang the world in future.Most known key pre-distribution scheme for distributed sensor networks, they use a lot of combinatorial design and graph theory techniques. the result of the paper is about some combination design problem and the better scheme using combinatorial method. J. Lee and D. R. Stinson [21] proposed using mutually orthogonal Latin squares to construct orthogonal array, and use orthogonal array to construct strongly regular graph, so to construct the key pre-distribution scheme for distributed sensor networks. It is well known, for a given number n, the largest number of mutually orthogonal Latin squares is the most difficult and classic question. the result is not good due to the difficulty. in this paper we are interested in the improvement of Chang's[8] bound for the mutually orthogonal Latin squares, also we are interested in showing a new key pre-distribution scheme for distributed sensor networks and the completion of the scheme on computer.